Document EP 1 422 436, included with reference to this application, explains how to create a compensating balance spring comprising a silicon core coated in silicon dioxide and working alongside a balance wheel with a predetermined inertia to provide temperature compensation for said resonator assembly.
There are many advantages to manufacturing such a compensating balance spring, but they are subject to the disadvantages of any manufacturing process. In other words, the stage in which the balance springs are cut from a silicon plate is subject to a very low level of geometric dispersion, but this is still not negligible in the case of a compensating balance spring where a similar operation needs to be provided for each type of movement.